Automatic train control



Aug. 3, 1937. P. J, SIMMr-:N

AUTOMATIC TRAIN CONTROL 1925 2 Sheets-Sheet l Original Filed July 9 Aug. 3, 1937. P. `.L slMMEN AUTOMATIC `TRAIN CONTROL Original Filed July 9, 1923 2 Sheets-Sheet 2 WIW Patented Aug. 3, 1937 AUTOMATIC TRAIN CONTROL.

PaulJ; Simmon, Eden,` N. Y., assignor; by mesneassignments, to- The Union Switch & Signalf Company; Swissvale,l Pa.,...a. corporation of.

Pennsylvania Refiled fory abandoned application Serial. No.`.

650,246July 9, 1923.v This. application August 319'28, S'eraIfNo.- 297,150

, 9 Claims.

'Ifhisapplicationis `filed in lieu:` ofr abandoned application, Serial No. 650,246,11ed July 9; 1923: This. invention relatesA to railway signalling; particularly to systems in which there-'is both automatic and' manual control and moreY especially to those in which there are means` forv automatically indicating or recording `the progress of trains;

This invention is an Aimprovement on myv invention disclosed in Reissue Letters Patent No.

17,384, dated July'BO, 1929, and also an improve-v In the present invention fourV signals for the. safe and quick direction of" train movementsfor any number of sections of track are provided; each section being subdivided into-several blocks,

and controlled from a centralpoint such.as adispatchers oiiice,` interlocking tower, or` way station by an operator, if therei'sno trainin the section. That is, an operator having apluralityof'sections of trackY under his control may setup four different signal indicationsfor a train.` going inone direction. but if there is no train inL the section, he may instantlychange so as` to provide four signals forthedirection of train movements in thev opposite direction.

In order that the operator may intelligently govern trainv movements with the least delay, means are provided to automatically indicate or record the movement of trains athisoffice so that. he has knowledge ofthe location and progress of all trains under his jurisdiction.

A further object of the invention is to prevent the operator from setting upiproceed signalsover a section of track for both an east bound and? a. west bound movement at the same time and1 to` In describing,'theinvention in" detail,` reference is had to the 'accompanying drawings wherein I` have illustrateda preferred"physicalV embodiment ofvmy invention-and wherein like characters of reference designate corresponding parts through out the severald views and in which: j

Fig; 1V is a schematic representation ofthe apparatus and' circuits in the dispatchersoiiice and along `the track;`4 Fig; 2 is a schematic representation of the apparatus and circuits on the locomotive or car; and Fig. 3- is a modication of Figj. 1, `andshows a schematic representation of vpart of' the apparatusin the-dispatchers office and' along the 'track by which fixed signals are displayedinstead of cab signals'.

Fig; l: shows a single track consisting of` rails In and 2. Rail l is electrically continuous; Rail 2j isdivi-ded int-o sections. by means of insulating joints as 3 thus dividing the track1 into block sections-as A, B, C, D, E, F, and G. In blocks Band F are shown sidings as i` where trains can meet andpass each other. Since the apparatus andcircuits for each single track section between passing sidings are identical, only one complete single track` section has been shown in Fig. 1, but the dipatchers` control and the recording of train movements has been shown for two single track sections, thus switches as 5 and 6 control the signals of a section between bl'ocksB and 4F andiswitches as l and 8 control the signals of-a section east of block F. At the clearanceV point of thersidings` insulating joints as 3 electrically separate the straightportion of the siding fromthe main track in a manner and for a purpose well' knownlto those skilled in the art. l i

Each block is providedwith a track circuit, a trackbattery as It being located at one end of each blockand track relays as a, b, c, d, e, f, and gf near theotherfends ofeach block, constituting with their `connections to the rails, a track circuit well knownto those skilled in the art. Track relays b, d, and f control two armatures fasf9 and Irlllandtrack relays a, 0,'e, and g` control-..three armaturesas 9, l0', and Il. When there is nol train in theblock, the track relay for thatblock-is energized and; its armaturesfthrough their' respective front. contacts control certain signals, and when there isv a train in` the block, itstrack relay is deenergized anditsarmatures will close certainbackcontacts for'the'` purpose of: locking switchesE-, Sz, `'I and 8 and'making a record of' train movements as will be described in more detaili hereinafter..

Adjacent to `the track are.A located groups .of

train control rails as AI2 and AI3, BI2 and BIS, C|2 and CI3, D|2 and DI3, E|2 and EI3, F|2 and FI3 and GI2 and GI3. The letter prefix as B to train control rails I2 and I3 indicate that the rails are in block B and' similarly for the others. Train control rails I2 and I3 are on the right hand side of the center line of the track looking east, and control each bound movements into a block, and a similar group of train control rails on the opposite side of the track, that is, on the right hand side of the center line of the track looking west, control west bound train movements into a block. These west bound train control rails have been designated as A|4 and AIS, B|4 and BIS, C|4 and CIS, D|4 and DIS, E|4 and EIS, FI4 and FIS and G|4 and GIS. In Ieach group of train control rails, one is the home train control rail and located near the entrance to a new block and the other is a distant train control railv and located approximately the braking distance from the home control rail. Thus train control rail I3 isl the home train control rail for an east bound train movement and train control rail |4 is the home train control rail for a west bound train movement and train control rail I2 is the distant train control rail for an east bound train movement, and train control rail I5 is the distant train control rail for a west bound train movement.

Manually operable switches S and 1 in the dispatchers oflice when in position as shown in Fig. 1, make contact with spring contacts I1 and are thus connected to an alternating current source as 20'and when these switches are disconnected from contact I1, the circuit from. the alternating current source is broken. When switches 6 or 8 are in the right oblique position, they make electrical contact with spring contacts as I8 and are thus connected with the positive pole of battery 2|, and when switches 6 or 8 are in the left oblique position, making electrical contact with spring contacts as I9, they are connected with the negative pole of battery 22. When switches 6 or 8 are open,I theyare disconnected from both direct current sources 2| and 22. Alternating current source 20 and direct current sources 2| and 22 are preferably located in the dispatchers office.

The east bound train control rails for the section of track from B to F are connected through the several armatures of the track relay of the block ahead to a line wire as 23 and the west bound train control rails for the section of track from F to B are connected through the several armatures of the track relay of the block ahead to a line wire as 24. Properly housed along the track are polarized relays as 2S, shown in blocks B and F, one being necessary for each section of single track between passing sdings. When polarized relay 2S kis positively energized, its polarized armature as 26 will swing to the right as shown in Fig. 1, and an electrical connection is made between it and line wire 23, through the contact 21 and when polarized relay 2S is negatively energized, its polarized armature will swing to the left, opposite to that shown in Fig. l, and will make an electrical connection with line wire 24 through the contact 28.

When switches 6 or 8 are in the right oblique position making contact with spring contact |8, polarized relay 2S is positively energized, and when in the left oblique position, thus making contact with spring contact I9, relay 2S is negatively energized, and when switches 6 or 8 are disconnected from either spring contact I8 or I9, polarized relay 2S is deenergized and neutral armature 29 will break away from front contact 30.

Polarized relay 2S which controls the section between blocks B and F is positively energized through the following circuit: From positive pole of battery 2|, wire 3|, impedance 32, bus 33,1wire 34, spring contact I8, switch 6, shaft 3S, wire 36, relay 31, wire 38, impedance 39, wire S0, terminal 5I, wire S2, terminal S3, wire 40, polarized relay 2S, wire 4|, resistance 42, wire 43, impedance 44, wire 4S, track rail I, and wires 46 and 41, to negative pole of battery 2|.

Relay 2S is negatively energized through the following circuit: From positive pole of battery 2, wires.48,49 and 46, track rail I, wire 4S, impedance 44, wire 43, resistance 42, wire 4|, polarized relay 2S, wire 40, terminal S3, wire S2, terminal SI', wire S0, impedance 39, wire 38, relay 31, wire 36, shaft 3S, switch 6, spring contact I9, wire 54, bus SS, impedance S6, wire S1, to negative pole of battery 22.

Impedances 32, 39, 44 and S6 are inserted in the circuit to prevent the flow of alternating current in the circuit and resistance 42 is inserted in the circuit for a purpose which Will be more fully described hereinafter.

When the dispatcher places switch 6 in contact with spring contact I8, polarized relay 2S is positively energized and thus all east bound train control rails between blocks B and F are electrically connected to battery 2| in the dispatchers ofce by reason of polarized armature 26 making contact with contact 21. however all west bound train control rails between Yblocks F and B are deenergized, since polarized armature 26 is disconnected from contact 28. When the dispatcher places switch 6 in contact with spring contact I9, polarized relay 2S is negatively energized and thus all west bound train control rails between blocks F and B are electrically connected to battery 22 in the dispatchers o'ice by reason of polarized armature 26 making contact with contact 28. Under these conditions however all east bound train control rails between blocks B and F are deenergized since polarized armature 26 is disconnected from contact 21. When the east bound train control rails are connected through polarized armature 26 and contact 21 to switch 6, they may be also charged with alternating current from alternating current source 20 through a circuit which will be more fully described hereinafter and similarly when the west bound train control rails are connected through polarized armature 26 and contact 28, they may also be charged with alternating current.

Since the circuits to the east bound train control rails for the positive direct current and the alternating current are common from polarized armature 26 to the train control rails, I will first describe the positive direct current from battery 2| to polarized armature 26, which is as follows: From positive pole of battery 2|, wire 3|, impedance 32, bus 33, wire 34, spring contact I8, switch 6, shaft 3S, wire 36, relay 31, wire 38, impedance 39, wire S0, terminal SI, wire S2, terminal S3, wire S8, armature 29 of relay 2S, front contact 36, wire S9, polarized armature 26, to contact 21. The alternating current circuit is as follows: From alternating current source 20, wire 60, condenser 6|, bus 62, wire 63, spring contact |1, switch S, shaft 3S, wire 64, alternating current relay 65, wire 66, condenser 61, wire 68, terminal Under these conditions `ico wire 52, terminal 53, w'ire'l58, armature 25,;

front contact 30, wire59, polarized armaturev 25, contact 21. Inthe, eventlthat polarized relay `25 being deenergized by reason of switch 6 being open, a by-pass circuit vis provided for the alter- 10 are inserted in the circuitslto-prevent the flow of direct current in the circuit. l

The circuitfrom polarized armature ,25` for both positive direct current and alternating current to train control rails Bl2 and B13 isas foli lows: From polarized armature 25, contact 21,

line wirel23, Wire 12, armature 5 ofrtrack relay c, front` contact 13, wire 15, to train control rails B13 and B12, and thence the circuit is completed to the current source in the dispatchers `oflice as will be more fully described hereinafter. .The circuit from polarized armature25 to train con trol rails CE2 and ,CIS is as follows: From polar ized armature 25, contact 21, line wire 23, Wire 11, armature 9 of track relay d, front contact 12, Wire15 to train control rails C13 'and C12. The circuit to train control rails DiS Yand D42 is as follows: From polarized armature 25, contact 21, line wire 23, wire 19, armature 9 of track relay c, contact 13, wire 80, to train control rails D13 and D12. The circuit to train` control rails E12 and E13 is as follows: From polarized armature ,25, Contact 21, line wire 23, wire 8i, armature 9 of track relay f, front Contact 13, wire 82, armature Il of track relay g, front contact 15, wire S3, to train control rails E13 and Ei2. Through Ithese two circuits, the positive direct current circuit and the alternating current circuit, east bound train control rails may be Velectrically condi.- tioned in four diierent ways as follows:

First condition-When switch 6 is in contact with spring contact I8 and switch 5 is in contact with spring contact l1, the east bound traincontrol rails are charged with positive direct current and alternating current.

`.Secomil condz'tzomf-When switch 5 is in contact with spring contact 18 and switch 5 is ,discon` nected from spring contact i1, the east bound train control rails are charged withpositive direct current only. l

Third condition-Wltien switch 6 is disconnected from spring contact i8 and switch 5 is in contact with spring contact l1, the east bound train control rails are charged with alternating current only. l

Fourth condition-When switch 5 isidisconnected from spring contact it and switch 5 disconnected from spring contact I1,.the `east bound train control rails are deenergized. Y

By reason ofthese four different electrical conditions, four different signals may be displayed on the east bound locomotive when the locomotive `is passing a train control rail, Vas will be morefully described hereinafter.

When the dispatcher places `switch 5 in'contact with spring contact i9, polarized relay is nega-Y tiveiy energized and all west boundtrain control rails are electrically connected throughpolar- Y ized armature 25 and Contact 28: and under these conditions west bound train control rails may also be charged with alternating currentashereinbefore stated. i i

Since the circuit to the west boundtrain control rails` for the negative direct current, and the alternating current, are common from polarized armature .25, tov the `train controlirails, I. will Yfirst describe the negative direct current circuit from battery 22 to polarized armature-25 which is as follows: From negative pole of battery 22, Wire 51,A impedance` 55, bus 55, wire 54, spring contact I9, switch 6, shaft 35, wire 35, relay 31, wire 38, impedance 39, wire 55, terminal 5l, wire 52, terminal 53, wire 58, armature 29, of polarizedrelay 25, front contact 35, wire 59, polarized armature 26, to contact 28. Y

, A1"he alternating current circuit for charging west bound train control rails with alternating` current as far as polarized armature 25 is con- Cerned is the same as hereinbefore described., ,l

.The circuit from polarized armature 25 for both negativedirect current and alternating current to train control rails F14 and F15 is as follows: From polarized armature 25, contact 28, line wire 24, `wire 84, armature 15 of track relay e, front contact 14, wire 85, to train control rails FM and F and thence the circuit is completed to the current sources in the dispatchers office as will be more fully described hereinafter. The circuit to train control rails EM and E15 is as` follows: From polarized armature, 25, contact 28, line wire 24, wire 86, armature i5 of `trackrelay d, `front contact 14, and wire 81 to train control rails E14 and El5. The circuit., to train control rails D14 and D15 is as follows: From polarized armature 25, contact 28, line wire 24, wire 88, armature I5 of track relay c, front con tact 15, and wire 89, to train control rails DH1r and Dl5. The circuit to train control rails `Gilt-land. Cl5 is as follows: From polarized armature 25,` Ycontact 28, line wire 24, wire 95, armature Il of track relay a, front contact 15, wire 91,'armature ,t

1li of track relay b, front contact 15, and wire 92,` to train control rails C15 and C15. Through these two circuits, the negative direct current circuit and the alternating current circuit, west bound train control vrails may be electrically conditioned in four different ways as follows: f

First condition- When switch 5 is in contact with spring contact i9 and switch 5 is in contact with spring contact l1, the west bound train control rails are charged with negative direct and alternating current.

Second conditon.-When switch 6 is in contact. with spring contact I9 and switch 5 is disconnected from spring contact I1, the west bound train control rails are charged withnnegative drect current only.

Third condition.-When switch 6 is disconnected from spring Contact 19, and switch 5 is in.- contact with spring contact I1, the west bound train controls rails are charged with alternating current only.

Fourth, condition-When switch 6 is discon-V nected from spring contact I9, and switch 5 is disconnected from spring Contact I1, the west bound train control rails are deenergized.

By reason of these four diierent electrical con-v ditions, four different signals may be displayed on A a west bound locomotive, when a locomotive is passing a train, control rail, as will be more fully described hereinafter.

It will thus be see-n that the dispatcher may condition the single track section between blocks Band F for an east bound train movement by placing switch 5 in contact with spring contact 18 underwhich conditions all east bound train control rails in the section maybe electrically conditioned in four different Ways as hereinbeforedescribed and when the dispatcher places switch 6 in contact with spring contact 19, the single track section; from :block F to block. B conditioned for a West bound train movement and similarly the train control rails may be electrically conditioned in four different ways as hereinbefore described. In addition to the dispatcher's manual 5 control of the electrical conditions of the train control rails, automatic control is also provided by means of a track circuit. Assume that there l is no train in any of the blocks between B and E, and the dispatcher has set up an east bound 107 movement by placing switch 6 in contact with spring contact I8 and a train received a clear signal at train control rail BI3 and proceeds into block C, then as soon as the train entered block C, the current from track battery I6 of block C is short circuited through the wheels and axles of the train and therefore track relay c becomes sufficiently deenergized so that its armatures will drop away from the front contacts. When this occurs train co-ntrol rails BI2 and BI3 become deenergized since the circuit is now broken by armature 9 of track relay c dropping away from front Contact 13. As soon however as the train has left block C and entered block D, track relay c again becomes energized thus again closing the circuit to train control rails BI2 and BI3 and a second train may proceed eastward with a clear signal. It will therefore be seen that a train which proceeds over the road automatically protects itself in the rear, so that a following train will automatically receive a danger signal when it arrives within braking distance of a train ahead. The same automatic rear end protection I by means of a track circuit is` also provided for West bound movements. For instance a West bound train entering block E will deenergize track relay e, thus breaking the circuit at front contact 14 of track relay e and deenergizing west bound train control rails F|4 and FI5. As soon, however, as the train has left block E, train control rails F|4 and FISV are again energized thus permitting a following train to proceed with a clear signal.

It will be noted that the circuit to train control rails E|2 and E|3 and G|4 and G|5 are taken through the armatures of both track relays f and g and f and e, the object being as follows: If the dispatcher has placed switch 6 in contact with spring contact I8, thus setting upan east bound movement for a train from block B to block F and also placed switch 8 in contact with spring contact |9, thus setting up a west bound movement for a train from block G to block F, the two trains will have to meet and pass each other at the siding in block F. If now the east bound train entered block E approximately at the same time that the west bound train entered block G, each train will automatically receive a danger signal, by reason of the track circuit control, before reaching block F and this will give the trains ample distance to slow down or stop until one of the trains has taken the siding. This arrangement is desirable if block F and the siding are relatively short. While this arrangement shows the preferred form, it is not absolutely necessary particularly if block F and the siding are relatively long. The arrangement of taking the circuit to the train control rails through two track relays, can also be obviated by placing the distant train control rails F|2 and F|5, a sufllcient distance back to give the engineer ample warning to stop for the meet. Switches 1 and 8 control the single track section east of block F through polarized relay 25 at block F in the identical manner as described for the section of B to F, and where A15 the dispatcher controls the train movements over a large number of single track sections from one central point, duplicate control switches as 5 and 6 with their corresponding circuits are provided for-each section.

The system is so arranged that when the dis- 5 patcher has set up an east bound movement from block B to block F by placing switch 6 in contact with spring contact I8, as soon as the train enters block C after receiving a clear signal at BI3, switch 6 is automatically locked in the position it 10 is in, so that it cannot be moved by the dispatcher, and the switch remains locked until after the train has passed out of block E. This is accomplished Yin the following manner: Switches 6 and 8 are rotatable on a shaft as 35. l5 Secured to the shaft is a disk as 93. In the periphery of this disk are two notches as 94 and 95. The armature 96 of relay 31 is hinged at 91. At the other end of armature 96, is a detent as 98 so positioned that when switch 6 is in contact 20 with spring contact I8, detent 98 will be in alignment with notch 94 and when switch 6 is in contact with spring contact I 9, detent 98 is in alignment with notch 95. When relay 31 is sufficiently energized it will attract its armature 96 and if 25 detent 98 is in alignment with either notch 94 or 95, it will engage one of the notches,. thus preventing the switch from being turned from the position it is in as long as relay 31 is sufciently energized. When relay 31 is not suf- 30 ciently energized, a spring as 99 pulls detent 98 out of engagement with the notches in disk 93. When switch 6 is in contact with spring contact I8, the normal position for an east bound train movement, and there is a train in either blocks 35 C, D, or E, relay 31 is sufliciently energized and thus the switch is locked as long as the train remains in the blocks C, D, or E. When block C is occupied by an east bound train, relay 31 is energized through the following circuit: From 40 positive pole of battery 2|, wire 3|, impedance 32, bus 33, wire 34, spring contact I8, switch 6, shaft 35, wire 36, relay 31, wire 38, impedance 39, wire 50, terminal 5| wire 52, terminal 53, wire 58, armature 29 of polarized relay 25, front con- 45 tact 30, wire 59, polarized armature 26, contact 21, line wire 23, wire 12, armature 9 of track relay c, back contact |00, wire |02, track rail and Wires 46 and 41 to negative pole of battery 2|. When this circuit is closed relay 31 is sufficiently 50 energized to attract armature 96 against the tension of spring 99 so as to lock switch 6, for the reason that a shunt circuit is now established which cuts out the resistance 42 in the circuit controlling polarized relay 25. When block D is 55 occupied relay 31 is energized thus locking switch 6 through the following circuit: From positive pole of battery 2|, wire 3|, impedance 32, bus 33, wire 34, spring contact I8, switch 6, shaft 35, wire 36, relay 31, wire 38, impedance 39, wire 59, 60 terminal 5|, wire 52, terminal 53, wire 58, armature 29, front contact 30, Wire 59, polarized armature 26, contact 21, line wire 23, wire 11, armature 9 of track relay d, back contact |00, Wire |03, track rail I, and wires 46 and 41 to negative pole 65 of battery 2|. When block E is occupied, relay 31 is energized, thus locking switch 6 through the following circuit: From positive pole of battery 2|, wire 3|, impedance 32, bus 33, wire 34, spring contact I8, switch 6, shaft 35, wire 36, relay 31, 70 wire 38, impedance 39, wire 50, terminal 5|, wire 52, terminal 53, wire 58, armature 29, front contact 30, wire 59, polarized armature 26, contact 21, line wire 23, wire 19, armature 9 of track relay e, back contact |00, wire |04, track rail I,

landwires 4'6andf41 to negative pole of battery f2`I. It vvillthus-belseen thatfasllong as anfeast bound vltr-ain occupies either blocks C, D, or E fdetent T98 #engages notch 'L94 thus locking switch .i5 7126 in thefpositionitiisin.

When switch 6 is in contact with spring 'contact "I '9, fthe normal position I for I a west 'i bound vtrain I movement,an`d there"is atrainin either `blocks E,FD,or C, Irelay-131 is suicientlyenergized and 10 lthusthe switch'is locked'as long .as'the train remainsfini-blocks E, D, or'C. When blockSE is occupied; relayi31 is energize'd thus locking switch `(i `through Stheffollowing circuit: VFrom positive lpole-of battery 22,1wires'i48,.49 .and 45,2track rail i, E-wire |304, back contact IIJI, armature II) of track Hrelay e, lwiref 84, line wire` 24; contact. 28polarized vf-arrriature .26 lof"relay:25,` wrer5'9, front contact "V30, armature .2229; wire 58,'iterminal 153,:-Wre 52, terminal 5I, Wire5ll, impedancell, wire 38, relay P313 wire36,shaft 535, :switch'r6; spring contact I9,

Wiref54, bus 55,1impedance56, and Wire 51, to #negativelpoleiofbattery ZZ.Y -`When' block D is f 'occupiedyrelay 311' is' energizedi thus locking switch 'i6 through thefollowing circuit: From `positive 1.25 V-polelo-f batter'yZZ, Wires 418,49 and 46,1 track rail TL/wire Ill'3, back contact IIlI,armature I0 of 'track relayd, `Wire86,:line-Wiref24, contact 28, polarized 'armature "26,".Wire `59, front` contact 1530; armature 529, Wire 58,terminal 53', Wire 52,

#31,?Wire3`6, shaftl35, switch 6, spring contact` I9, Wire'f54, bus 55,1i1npedance :55, and wire51to "negativepole ofribattery 22;I .fllllienv block C .-is f occupied relay 31 Eisvenergized thus locking switch 1 35 `I through (the fol-lowingcircuit: From 4positive fpole of batteryi22fwires'48, 49 and' 46, track rail LI, 'Wire `|I)2,backcontact IIlI,V armature IIJ` of "vtrack'relay c,'wire'88.linelwire 24, contact 23, i 'polarized iarmaturef 26, `Wire 59, front:contact l30,

40- armature 29, Wire-58,lterminalr53,-Wire:52, terminal'fEIfwire50,:impedance 39,*Wireu38, relay "-31,1 Wire'i36, shaft'35,switchlspring contact I9, `iwiresf54uandfi55; impedance 5'5,` andf Wire 51y to negative lpole -of"bat-tery 22.

5145 i-Itmiill thus lbe seenthatwhen the dispatcher hassetup'fan east `boundy movement from `block Bftofbloclr:LY and `aftrain`4 has-accepted a clear or'lproceed signal-and has entered block C,..the "dispatcher issunablefto change the posltion of .50sv`1`itch '61 untill-the train has vleft block.Ep.and vvvheni.theVdispatcherhas set up a West bound fimove'ment from b1ock-F-to :block C and a train l has ac'cepteda" clear or proceed signal and `has entered block `the dispatcher -s .unable to i o55'"`charige'thef position ofwswitch until, the train `-as` the .it-rain has'reached the main track or the ifs'idingwofblock B or-F. A similar locking vmeans may Salsov be provided Lfori alternatingcurrent m"'switehesl 51 and? .1. Theflockingrmeans are the l "sa'mcexcept that only one notch as W55 is` necesalternating current. When switch 5 is in contact `with spring contact I1 and an east bound train has entered block C, relay B5-becomes sufficiently energized thus lockingswitch '5 in the position it yis in through the ,following circuit: From alter- 5 `nating current sources 120, wire I'fl,- condenserl, vvires 152 and 53, spring contact I1, switch 5,shaft "55, Wirefl, re1ay`55, Wire-66,-condenser 61, wire v58, terminal "5I, wire `52, terminal 53, Wire 53,

armature29,i front contact g3.0, wire159, polarized i 10 Iarmature26, contact `'.21,line=Wir -:-23, wire 12, .armature `9 of track relay c, back contact |00, 'Wire m2, track rail I, and Wires 146, 49 and -I06 to alternating current source' 20.

Since the circuits for the purpose of lockingl switch: 5 through blocks D and E forboth east boundas fwellaswes't' bound movements are similar,fasthe circuits described for `switch 6, it is thought not necessary to describe these in further detail.

.Under some conditions of operation underthis .system,.it may be desirable not to lock switches 5 and 1, controlling the alternating current in the :,positionrtheytare in,1even if blocks E, D and C are occupied,so as to givethe dispatcherlthe25 liberty to `move this switch tol the closed or open position at alltimes, in which case the locking feature for these switches 5 andf 1 may beomitted.

,l l Lwill `nowrdescribe the apparatus on the loco- ;y motive or `car capable of displaying four diierentiBO .signals corresponding to the Vfour different elec- 4trical conditions of the train control rail when .passingiai train control ra'il,-and also how these .signals .are continued after the locomotive has passed the train control rail. In Fig. 2, are shown "-135 four signals Vdesignated as-No. 1, 1\To.'2,rl\lo.` 3, and No.ll. While these devices areshown as lamps .andjdesignated signals, they mayV equally as well representan electro-magnetic device to which fmotionlisjgiven, 'depending upon whether theao circuit is energized or deenergized and suchelectro-'magnetic devices may be usedV for other purposes than, or :in addition, to, the display `of sig- 'A nalsf tolthe engineer, `such as vis .well known in the art, ,theproper control of speed control de- A45 -`vices: or.` pneumatic air valves for both.

.Signal'No l,.is` displayedwhen the locomotive :Lisripassing a train: control rail which is positively s energized withvdirect current and alternating A`current.` Signal No. when the locomotive is,.50

passing` a train control rail which is energized `With Jpositive. or negative direct current only. f Signal No. 3 is displayed when the locomotive is passinga train control railf-Which is energized with alternating" current only. Signal No. 4 is 55 displayed-When 'the locomotive is passing a train control railswhi'ch is entirely deenergized.

In Fig. 2 is` shown an electrical contact shoe as .151 so positionedvon ithe locomotive as to make ,contact With traincontrolfrails. 'The contactf sl'ioe is hinged at 108. The train control rails `are inclined at `the ends so as-to form a ramp in the usual manner such as is shown in my prior *Patent -1\To. 1,140,623 granted May 25, 1915.

When the. Contact shoe slides along this ramp 65 Ethe vshoe is tilted so as to break`-contacts as H19,

Il andL III. When the` shoe leaves the other L end of ithe train control-rail,-a spring as II2 J `forces Athe contact shoe to` thenormal position, l thus again closing contacts 1119, IIIlv and III.

The locomotive also carries a polarized relay `'as IIS, an alternating'current relay as II4 with its direct current coil as I I 5, and two batteries as "IIIa and VI I1.A Polarized relay II3 controls three ,fneutralarmaturesas I,I8, IISand I20 and two 75 .polarized armatures as |2| and |22. Polarized armatures |2I and |22 are members of a pole changing switch for the purpose of changing the direction of the ow of current from battery I6. When polarized relay ||3 is positively energized its neutral armatures make contact with front contacts as |23, |24 and |25 and its polarized armatures are in the position shown in Fig. 1, and make contact with contacts |26 and |21. When polarized relay I|3 is negatively energized, its neutral armatures make contact with `their respective front contacts but the polarized armatures are now in the position opposite to that shown in Fig. 2, and make contact with contacts |28 and |29. When polarized relay I I3 -is deenergized, its neutral armatures ||9 and |20 make contact with back contacts |30 and I3I. When alternating current relay ||4 or its com- 'panion direct current coil H5 is energized, its armatures |32 and |33 make contact with front contacts |34 and |35 and when this relay is deenergized, armature |33 makes contact with back Contact |36.

When an east bound locomotive is passing an east bound train control rail as for instance B|3, which is energized with positive direct current and alternating current, polarized relay ||3 is positively energized through the following circuit: From positive pole of battery 2|, wire 3|, impedance 32, bus 33, Wire 34, spring contact I8, switch 6, shaft 35, wire 36, relay 31, wire 38, impedance 39, Wire 50, terminal 5|, wire 52, terminal 53, Wire 58, armature 29, front contact 30, wire 59, polarized armature 26, contact 21, line Wire 23, wire 12, armature 9 of track relay e, front contact 13, wire 16, train control rail BI3, contact shoe |01, wires |31 and |38, impedance |39, wire |40, polarized relay II3, wires |4I, |42, |43 and |44, resistance |45, wire |46, axle |41,

wheel |48, track rail and wires 46 and 41 to negative pole of battery 2|. A circuit is also established through alternating current relay ||4 as follows: From alternating current source 20, wire 60, condenser 6|, bus 62, wire 63, spring 45 contact I1,`switch 5, shaft 35, wire 64, relay 65,

wire 66, condenser 61, wire 68, terminal 5|, wire 52, terminal 53, wire 58, armature 29, front contact 30, wire 59, polarized armature 26, contact 21, line Wire 23, Wire 12, armature 9 of track relay c, front contact 13, Wire 16, train control rail BI3, contact shoe |01, Wires |31 and |49, condenser |50, wire |5I, alternating current relay ||4, wires |52, |42, |43 and |44, resistance |45, wire |46, axle |41, Wheel |48, track rail I,

and wires 45, 49 and |06 to alternating current Vsource 20. With relay ||3 positively energized and relay I4 energized, a circuit is established through signal No. 1, as follows: From positive pole of battery I I6, wires |53 and |54, contact |26, polarized armature |2I, wires |55 and |56,

armature |33 of relay ||4, front contact |35, wire |51, armature ||9 of relay ||3, front con- -tact |24, wire |58, signal No. 1, Wires |59, |60, |43 and |6I, polarized armature |22, contact |21, and wire |62 to negative pole of battery I6.

When the contact shoe |01 leaves the other end of the train control rail, the contacts |09, ||0 and are again closed and two stick circuits are established, a positive direct current stick circuit and an alternating current stick circuit.

The positive direct current stick circuit is as follows: From positive pole of battery ||6, wires |53 and |54, contact |26, polarized armature I2I, wires |55, and |63, armature ||8, of relay II3, front contact |23, Wire |64, contact |09,

contact shoe |01, Wires |31 and |38, impedance |39, wire |40, polarized relay II3, wires I4|, |42` and |6I, polarized armature |22, contact |21, and wire |62 to negative pole of battery ||6. The alternating current relay stick circuit is as follows: From battery II1, wire |65, coil ||5 of relay II4, wire |66, contact metallic con-I tact plate |61, Contact IIO, wire |68, front con tact |34, armature |32, of relay |I4, and wire |69, to negative pole of battery ||1. Metallic plate |61 is attached to Contact shoe |01 but insulated therefrom, sov that when the Contact? shoe slides on a train control rail, contacts ||0 and are broken. With the positive direct current stick circuit and the alternating current relay stick circuit in effect, signal No. 1 is con-I tinued until the next train control rail is reached.`

Assuming now that an east bound train is passing train control rail BIB and this rail is energized with positive direct current only then polarized relay |I3 on the locomotive will be positively energized through the circuit hereinbefore described, but alternating current relay stick circuit was broken as soon as the contact shoe |01 slid onto the rail.

. |26 polarized armature |2|, wire |55 and |56,

armature |33 of relay ||4, back contact |36, wire |10, armature |20, of relay ||3, front contact |25, wire |1I, signal No. 2, wires |12, |13, |60, 43 and |6I, polarized armature |22, contact |21, and wire |62 to the negative pole of battery I6. When the contact shoe leaves the other end of the train control rail, the positive direct current stick circuit is again established as hereinbefore described but the alternating current relay stick circuit is still inoperative. While contact |09 is again closed through contact shoe |01, this stick circuit is now open at front contact I 34. Thus signal No. 2 will be continued l until the next train control rail is reached.

Assuming now that an east bound train is passing train control rail B| 3 and this rail is energized with alternating current only, then polarized relay ||3 on the locomotive will be deenergized since the positive direct current stick circuit is now open at contact |09, but alternating current relay ||4 will be energized through the circuit as hereinbefore described, with this difference however that since the circuit is now open at armature 29 and front contact 30 by reason of polarized relay 25 being energized, the alternating current will reach train control rail B|3 through the by-pass from terminal 53 to polarized armature 25 as hereinbefore described. With alternating current relay ||4 energized but polarized relay ||3 deenergized, a circuit is established through signal No. 3 as follows: From positive pole of battery IIE, wires |53 and |54, contact |26, polarized armature |2|, wires |55 and |56, armature |33 of relay II4, front contact |35, wire |51, armature |I9 of relay ||3, back contact |30, wire |14, signal No. 3, wires |15, |13, |60, |43 and |6I, polarized armature |22, contact |21, and wire |62, to negative pole of battery ||6. When the contact shoe leaves the other end of the train control rail, the alternating current relay stick circuit is again established as hereinbefore described but the positive direct current stick circuit is now inoperative 40 patchers office of the movement of trains.

through the circuit. Resistance is inserted in the cab circuit for the following purpose: When there is a train in blocks C, D or E, current is ilowing through relays 31 and 65 in the dispatchers oflice thus locking switches 6 and 5 in the position they are in as hereinbefore described. When contact shoe |01 on the locomotive is passing an energized train control rail, current is also flowing through relays 31 and 65, but by reason of the combined resistance of relay II3 and resistance |45, or relay II4 and resistance |45, there is not sufficient current owing through these relays to attract their armatures 96 against the tension of spring 99, therefore, a train passing a train control rail which is energized Will not lock switches 5 or 6. For instance, it is desirable when there is a train in block B that the switches governing the adjacent sections of track be unlocked and it is possible that a contact shoe on a locomotive may be in contact with either train control rails BI 2 or BI 3 or B I 4 or BI 5 and this would lock the switches if the current flow through either relay 31 or 65 is not reduced as arranged by the introduction of the necessary resistance |45 in the cab circuit.

The four signals on the locomotive may be used for any purpose the railway management species. For instance, signals No. 1 and No. 4 may be used for safety purposes, signal No. 1 indicating to the engineer to proceed, that the track ahead is clear and signal No. 4 to stop, that there is danger ahead. Signal No'. 2 may be used for facility purposes, thus signal No. 2 may indicate to an engineer to stop at the next siding, pull in on the siding and pass another train, while signal No. 3 may indicate to the engineer to stop at the next siding and report to the dispatcher.

I will now describe the means by which a record is'made or an indication is given in the dis- In the dispatchers office is a suitably mounted record sheet as |18 driven by a roller as |19 which in turn is driven by a shaft as |80. Shaft |80 receives motion through ratchet wheel as IBI.

Y"45 A pawl as |82 is pivotally attached to armature 'other side, of battery |90.

|83 of electromagnet as |84, the armature being hinged at |85. When electromagnet |84 is periodically energized motion is given to ratchet Wheel I8I by pawl |82. A spring as |86 normally pulls-armature I 83 and pawl |82 to the right When electromagnet |84 is not energized. Electromagnet |84 is connected by wire |81 to a make and break device as |88, which make and break device is periodically operated by a clock asl |89. This may well be of the form as shown in my prior Patent No. 1,203,146 granted October 21, 1916. When the make and break device is closed, electromagnet |84 is energized through the following circuit: From battery |98, wires I9I and |92, electromagnet |84, wire I 81, make and break device |88, wire |93, and wire |94, to the The make and break device |88 is operated say every ve seconds, so as to give a slow and uniform motion to record sheet |18 through ratchet wheel I8I and pawl |82.

Thel record sheet |18 is transversely divided into sections as |95 and |96, each section representing a section of single track between passing sidings or other points where trains may pass each other. The record sheet is longitudinally divided into time lines, such as 1 A. M., each one of the lines representing a one minute interval. It will thus be seen that longitudinally the record sheet assumes a constantly changing position during the 24 hours of the day.

Adjacent to the record sheet are located perforating magnets as |91, |98 and |99, three for each section of single track. These perforating magnets control armatures 200. Pivotally attached to armatures 200 are perforating needles as 20|, so positioned adjacent the record sheet that when a perforating magnet is energized a perforation is made in the record sheet.

Perforating magnet |91 of section |96 records east bound train movements through blocks C, D and E, and perforating magnet |98 records west bound train movements through blocks E, D and C. Perforating magnet |99 records whether the train control rails represented by section |96 are energized with alternating current or not when there is a train movement in either direction in blocks C, D or E. As hereinbefore described, when blocks C, D or E are occupied by either an east bound or by a west bound train and switch 6 is in contact with either spring contacts I8 or I9, relay 31 is sufficiently energized to attract its armature 96. Attached to armature 96 but insulated therefrom is a metallic contact plate as 202 and when armature 96 is in the energized position, this plate contacts with contacts 203 and 204 thus closing the circuit through perforating magnets |91 and |98 at this point. Also attached to switches 5, 6, 1 and 8 but insulated therefrom are metallic contact plates 205 and 206. When switch 6 is set up for an east bound train movement thus making contact with spring contact I8, metallic plate 205 makes contact with contacts 206 and 201, thus closing a circuit through perforating magnet |91 at this point. The circuit through perforating v magnet |91 is as follows: From battery |90, wires |9I and 2I0, contact 2| contact plate 2|2, contact 2| 3, bus 2| 4, wire 2I5, perforating magnet |91, wire 2I6, contact 206, metallic plate 205, contact 201, Wire 2 I1, contact 203, metallic plate 202, contact 204, wires 2I8 and |94 to opposite side of battery |90.

When switch 6 is set up for a west bound movement thus making contact with spring contact I9, metallic plate 206 makes contact with contacts 208 and 209, thus closing the circuit through perforating magnet |98 as follows: From battery |90, Wires I9I and 2I0, contact 2|I, metallic plate 2I2, contact 2|3, bus 2I4, wire 2I9, perforating magnet |98, wire 220, contact 208, metallic plate 206, contact 209, wires 22 I, and 2I1, contact 203, metallic plate 202, contact 204, wires 2I8, and |94, to other side of battery |90. l f

When switch 5 is in contact with spring contact I1 andthere is a train in either blocks C, D or E a circuit is closed through perforating magnet |99 as follows: From battery |90, wires I9I and 2I0, contact 2H, metallic plate 2I2, contact 2I3, bus 2I4, Wire 222, perforating magnet |99, Wire 223, contact 206, metallic plate 205, attached to switch 5, contact 201, wire 224, contact 203, metallic plate 202, contact 204, and wire |94 to the opposite side of battery |90.

It will be noted that the circuits through the perforating magnets are taken through a circuit breakingdevice as 2I2 so that these circuits are periodically made and broken. This circuit breaking device operates as follows: Metallic contact plate 2I2 is attached to armature |85 but insulated therefrom. Every time electromagnet |84 is energized which as hereinbefore stated is say every five seconds, the contacts 2II and 2I3 are closed through metallic plate 2I2. When electromagnet |84 is deenergized armature |83 is pulled to the right by spring |86 and the circuit through the perforating magnet is broken. By reason of this periodic breaking of the circuit a continuous perforation is made on the record sheet, as long as a section, of single track consisting of blocks C, `D and E is occupied by a train and switch 6 is in contact with either contacts |8 or |9 or switch 5 is in contact with spring contact I'|. VThus when an east bound train leaves block B with signal No. 1, perforating magnet |9i will start to perforate in section |96 of the record sheet and perforating magnet |99 will start to perforate in the same section as soon as the train has entered block C and these two magnets will continue to perforate until the train has left block E, thus recording the exact time the train entered the single track section and also the time the train remained in the single track section. Should this train proceed through the section with No. 2 signal only, perforating magnet |91 will perforate and should it proceed through the section with signal No. 3, only, perforating magnet |99 will perforate. Thus not only a reco-rd is made of the train movements but also a record of the kind of signal displayed on the locomotive. Similarly a west bound train will record its movement through the section through perforating magnets |98 and |99.

A dispatcher having a number of single track sections under his control thus knows what progress the trains are making under his supervision and can direct the train movements with the greatest dispatch by properly positioning the manually operable switches. rPhe system lends itself to different methods of operation which the railway management may consider the most suitable for their particular purpose. One of the methods of operation would be aS follows:

Assume that by reason of the accurateknowledge which the record sheet gives of the location of trains on his division, the dispatcher decides to have an east bound train meet a west bound train at siding F. He also decides to favori. the west bound train and therefore have the east bound train take the siding. In such case, he would then place switch I in contact withspring contact Il and switch 8 in` contact with spring contact |9, thus giving signal No. 1, the proceed signal, to the west bound train, up to train control rail Fi5. He also would place switch 6 in contact with spring contact I8 but open switch 5 so as to disconnect it from spring contact When the east bound train arrives at train control rail BIZ, signal No. 2, would be dipslayed on the locomotive, thus indicating to the engineer to proceed to the next siding, siding F, pull in o-n the siding, and meet another train. Train control rail FI5 being controlled by switch 6, and this switch being now in the east bound position, train control rail EI`5 would be deenergized and thus the west bound train would receive a danger signal sufliciently far back to stop for the meet. If the east bound train, or any portion of it should be in block E, the west bound train would receive its danger or stop signal at train control rail GI5, by reason of the track circuit control. As soon as the east bound train has pulled in on the siding and cleared the main track the dispatcher is" so advised by by telephone, as soon as they are in on the siding and have cleared the main track. With the knowledge that the east bound train is clear of the main track the dispatcher may place switch 6 in contact with spring contact I9V thus giving a proceed signal, signal No. 2, to the west bound train, at train control rail Flli.V It will be noted, however, that switch `(i was locked in the east bound position as long as the east boundv train occupied either blocks C', D or E, and the dispatcher could not move switch 6 into the west bound position thus giving a clear signal to the west bound train at train control rail FI4 until the east bound train was actually in the clear on the siding. Similarly should the west bound train have reached block C or F, before the east bound train reached block E, a danger signal wouldbe displayed to the east bound train at train control rails E|2 and EIS. In practice rails similar to train control rails as FI3 would also be placed adjacent to the siding on the right hand side of the-center line thereof looking east, and energized or deenergized through the same circuit as train control rail F|3. With this arrangement one of the track rails of the siding would also be electrically connected to track rail I. As soon as the west bound train has cleared the single track section east of block F, switch 8 is unlocked from its west bound position and the dispatcher may give a proceed signal to the east bound train standing over the train control rail on the siding by placing switch 8 in the east bound position in contact'with spring Contact I8.

If the dispatcher desires todisplay signal No. 3 to a train indicating to theengineer to stop and report to the dispatcher, he iirst places switches 9 or 8 in contact with either spring contacts I8 o-r I9, `depending upon which direction the train is running. He then places switches either 8 or 8 in the `neutral oropen position, so that they are disconnected from both springcontacts 8 and |9. He then places switches 5 or 'l in contact with spring contact I'| Athus energizing the third rails for the section with alternating current only, which will result in the display of signalNo.3.

It is, `of course, understood that in addition to the dispatchers control of the signals additional safety is provided by means of the track circuit control. Trains yapproaching each other will receive a danger signal, `'signal No. 4, when more than a `block apart..thusl giving ample distance to bring the train tov a stop, anda train following another will Vreceive a danger signal, signal No. 4, when ywithin braking distance of the occupied block ahead.

Theabove is one method of operation under` which the systemlmay be used but there are a number of other methods or modications which will be evident to those skilled in train operation.

`The modification shown in Fig. 3, is identical with Fig. 1e,` insofar as the circuits and recording means are concerned there is a difference, however, which consists in substituting fixed signals in place of the train control rails necessary for cab signals. The several blocks, track batteries, track relays and track relay armatures are identical with Fig. 1, as are also circuits from batteries 2| and 22 and alternating source in the dispatchers office, through the several positions of switches 5, E, 'i and 8. The circuits from polarized armature 28 of relay 25 to the train control rails are also identical except that for the -train controlrails two relays, as 22,5 and 226 at each signal point are substituted. These two relays, with the circuits they control are shown in Fig. 3, opposite block F, and these signals control the entrance for a west Vbound train from block G into block F. This detail arrangement of circuits controlled by relays 225 and 226 is represented at other blocks, as 221 for east bound signals and 228 for west bound signals',ythe circuits controlling the xed signals being identical for both directions. These relays may control both home and distant fixed signals in the manner well known to those skilled in the art.

It is thought suflicient to describe the circuits for the control of the west bound signals from block C to block F since the arrangement for other blocks for both directions is identical. In the detailed circuit diagram are shown four signals, designated as No. l, No. 2, No. 3 and No. 4. These signals are controlled by direct current relay 225 and alternating current relay 226. When relays 225 and 226 are both energized signal No. 1 is displayed. When only relay 225 is energized signal No. 2 is displayed. When only relay 226 is energized signal No. 3 is displayed, and when both relays 225 and 226 are deenergized, signal No. 4 is displayed.

When switch 8 is in contact with spring contact I9, normal for a west bound movement, relay 225 is energized through the following circuit: From positive pole of battery 22, wires 48, 49 and 46, track rail I, wire 229, resistance 230, wires 23| and 232,relay 225, wire 233, impedance 234, wires 235 and 236, front contact 14 of track relay F, armature I0, wire 231, front contact 15, of track relay e, wire 238, line wire 24, contact 28, polarized armature 26, of relay 25, wire 59, front contact 3|), armature 29 of relay 25, wire 58, terminal 53, wire 52, terminal 5I, wire 50, impedance 39, wire 38, relay 31, wire 36, shaft 35, switch 8, switch contact I9, wire 54, bus 55, impedance 56 and wire 51 to the negative pole of battery 22.

When svn'tch 1 is in contact with spring contact I1, relay 226 is energized through the following circuit: From alternating current source 20, wire 69, condenser 6|, bus 62, wire 63, spring contact I1, switch 1, shaft 35, wire 64, relay 65, wire 66, condenser 61, wire 68, terminal 5I, wire 52, terminal 53, wire 58, armature 29, front contact 30, Wire 59, armature 26, contact 28, line wire 24, wire 238, armature I I of track relay e, front contact 15, wire 231, armature ID of track relay f, front contact 14,.Wires 236 and 239, condenser 240, wire 24|, relay 226, wires 242 and 23I, resistance 230, wirey 229, track Vrail and wires 46, 49 and |06 to alternating current source 20.

Impedance 234 is placed in the circuit to prevent the flow of alternating current through the circuit, and condenser 249 is placed in the circuit to prevent the flow of direct current through the circuit. Resistance 239 is inserted in the circuit for the same purpose as resistance |45 is inserted in the cab circuit, that is, to reduce the flow of current through relays 31 and 65 in the dispatchers office so as not to lock the switches as hereinbefore described.

When relays 225 and 226 are both energized a' circuit is closed through signal No. 1, as follows: From battery 243, wire 244, armature 245 of relay 226, front contact 246, wire 241, armature 248 of relay 225, front contact 249, wire 250, signal No. 1, wire 25|, and wire 252 to opposite side of battery 243. When relay 225 only is energized a circuit is closed through signal No. 2, as follows: From battery 243, wire 244, armature245, back contact 253, wire 254, armature 255 of relay 225, front contact 256, wire 251, signal No. 2, wires 258 and 252 to the other side of battery 243. When relay 226 only is energized a circuit is closed through signal No. 3, as follows: From battery 243, wire 244, armature 245, front contact 246, wire 241, armature 248, back contact 259, wire 260, signal No. 3, wiresr 26| and 252 to opposite side of battery 243. When both relays 225 and 226 are deenergized a circuit is closed through signal No. 4, as follows: From battery 243, wire 244, armature 245, back contact 253, wire 254, armature 255, back contact 262, wire 263, signal No. 4, wire 264, and wire 252 to opposite pole of bat- 'tery 243. Relays 225 and 226 and battery 249 are properly housed near each signal location along the track.

While in the preferred form of my invention I have shown recording means to give the dispatcher knowledge of the location and progress of trains, I do not wish to be restricted to the recording means shown. Any means automatically indicating at the dispatchers ofce the location and progress of trains may be considered an equivalent within the scope of my invention. For instance, the perforating magnets |91, |98 and |99 may be indication lamps which are lighted when their respective circuits are closed; thus visibly indicating the location and progress of trains. Or the perforating magnets |91, |98 and |99 may be any form of electrical translating devices which indicate when the circuits through them are closed; thus the position of armature 290 in itself may be a visible indication to the dispatcher of the location and progress of trains.

The purpose of the invention is to provide a simple and inexpensive system of signalling for a railway where a track is used for both directions of trac. It is particularly adaptable to single track uses but it is equally adapted for two or more track lines Where it is desirable to use a certain track normally for one direction but at times to operate trains with dispatch and. safety in the opposite direction.

Although I have particularly described one of the physical embodiments of my invention and illustrated the same, nevertheless I desire to have it understood that 'the particular form illustrated is merely illustrative and does not cxhaust the possible physical embodiments of means underlying the principle of my invention.

What i's claimed is:

1. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections being separated by stretches of single track, each siding section having a signal station adjacent each end thereof for controlling the entrance of trains from the adjacent single track stretch into the siding section and each siding section having a signal station adjacent each end thereof for controlling the departure of trains from the passing siding section, each of the signal stations including different signals, the different signals of the first mentioned signal station being for indicating main track or side track operation, and each signal station having signal control means responsive to different kinds of currents supplied thereto for effecting display of said different signals, a dispatchers office, a line circuit extending therefrom for each siding section, and associated with the signal stations of the siding section for supplying currents thereto, means at the dispatchers office for impressing at least two diierent kinds of currents upon the line circuits, a relay at each siding sectionv associated with the line circuit and responsive to the polarity of one of said currents `in the line circuit for establishing the signal stations for one or the other direction of train movement, and means at the dispatchers cnice for chang- I ing the polarity of said one of said currents in the line circuit.

2. In a railway dispatching system, a trackway having passing siding sections being with' main tracks and side tracks, said siding sections separated by stretches of single track, each sidingsection having a signal station adjacent each l5 end thereof for controlling the entrance of trains from .the adjacent single track stretch into the siding section and each siding section having a signal station adjacenlt each` end thereof for controlling the. departure of trains from the passing siding section, each of the signal stations including different signals, the different signals of the rst mentioned signal stations being for indicating main track or side track operation, and each signal station having signal control means responsive to different kinds of currents supplied thereto for effecting display of said different signals, a dispatchers oice, a line circuit extending therefrom for each siding section and associated with the signal stations otthe siding section for supplying currents thereto7 means at the4 dispatchers oflice for impressing alternating and direct currents upon the line circuits, a relay at each siding section associated with the line circuit and responsive l to the polarity of one of said currents inthe line circuit for establishing the signal stations for one or the other direction of train movement, and meansA at the dispatchers o'ice for 4 changing the polarity of said one of said cur- 40 rents in the line circuit.

3. In a railway dispatching system, a trackway having passing siding sections being with main tracks and side tracks, said siding sections separated by stretches of single track, each siding section having a signal station adjacent each end thereof for controlling the entrance of trains from the adjacent single track stretch into the siding section and each siding section having a signal station adjacent each end thereof for controlling the departure of trains from the passing siding section, each of. the signal stations including different signals, the different signals of the iirst .mentioned signal stations being for indicating main track or side track operation, and each signal station having signal control means responsive to different kinds of currents supplied thereto for effecting display of said different signals, a dispatchers oflice,` a line circuit extending l therefrom for each siding section and associated with the signal stations of the siding section for supplying currents thereto, means at the dispatchers oflice for impressing alternating and direct currents upon the line circuits, a relay at each siding section associated withthe line circuit and responsive to the polarity of one of said currents in the line circuit for establishing the signal stations for one or the other direction of Itrain movement, means at the dispatchers office for changing the polarity of said one of said currents in the line circuit, and means at the dispatchers oice and controlled o-ver the line circuits for indicating the movement of trains along the trackway.

4. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections being separated by stretches of single track, each siding section having a signal station adjacent each end thereof for controlling the entrance of trains from the adjacent single track stretch into the siding section and each siding section having a signal station adjacent each end thereof for c'ontrolling -the departure of trains from the passing siding section, each of theI signal stations including different signals, the diierent signals of the first mentioned signal stations being for indicating main track or side track operation, and each signal station having signal control means responsive to different kinds of currents supplied thereto for effecting display of said different signals, a dispatchers oice, aline circuit extending therefrom for each siding section and associated with the signal stations of the siding section for supplying currents thereto, means at the dispatchers oiiice for impressing at least two different kinds of currents upon the line circuits, a relay at each siding section associated with the line circuit and responsive to the-polarity of one of said currents in the line circuit for Vestalznli'shing the signal stations for one or the other direction of train movement, means at the dispatchers ofce for changing the polarity of said one of said currents in the line circuit, and means at the dispatchers oice and controlled over the line circuits for indicating the movementV of trains along the trackway.

5. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections being separated by stretches of single track, each siding section having a ramp rail adjacent each end thereof for controlling the entrance of a vehicle from the adjacent singleftrack stretch into the siding section, and each siding section having a ramp rail adjacent 'each end thereof for controlling the departureof the vehicle from the passing siding section into the adjacent single track stretch, adispatchers cnice, aline circuit extending' from fthe 'dispatchers office for each siding section and associated with said ramp rails ofthe siding section, means at `the dispatchers cnice for selectively impressing direct and alter-Y nating currents upon the line circuit and for reversing the polarity of the direct current, a relay in the line circuit at the siding section end thereof, said relay-being responsive to thepolarity of the direct current for applying the line circuit current to the ramp rails of the siding section for one or the other direction of traiiic movement, and a vehicle on the trackway having signal means selectively responsive to the presence of direct current or both direct and alternating current for displaying different signal indications.

6. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections being separated by stretches of single track, each siding section having a ramp rail adjacent each end thereof for controlling the entrance of a vehicle from the adjacent single track stretch into the siding section, and each siding section having a ramp rail adjacent each end thereof for controlling the departure of the vehicle from the pass'- ing siding section into the adjacent single track stretch, a dispatchers oilioe, a line circuit extending rorn the dispatchers oice for each siding section and associated with said ramp rails of the siding section, means at the dispatchers oflice for selectively impressing direct and alter- 'nating currents upon the line circuit and forv reversing the polarity of the direct current, a relay in the line circuit at the siding section end thereof, said relay being responsive to the polarity of the direct current for applying the line circuit current to the ramp rails of the siding section for one or the other direction of traflic movement, a vehicle on the trackway having signal means selectively responsive to the presence of direct current or both direct and alternating current for displaying diierent signal indica.- tions, and means at the dispatchers ofce controlled over said line circuits for indicating the movement of the vehicle along the trackway.

7. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections separated by stretches of single track, each siding section having a ramp rail adjacent each end thereof for controlling the entrance of a vehicle from the adjacent single track stretch into the siding Section and each siding section having a ramp railadjaccnt each end thereof for controlling the departure of the vehicle from the passing siding section, a dispatchers office, a line circuit extending from the dispatchers oice for each siding section and associated with said ramp rails of the siding section, means at the dispatchers ofiice for impressing two different kinds of currents upon the line circuits, a relay at each siding section associated with the line circuit and responsive to the polarity of one current in the line circuit for connecting to the line circuit the ramp rails for one or the other direction of train movement, means at the dispatchers oiiice for changing the polarity of said one current in the line circuit, a vehicle on the trackway having signal means responsive to the presence of a. current in the ramp rails for displaying a proceed signal and responsive to the presence or absence of one kind of current in the ramp rail for displaying a main track and a side track indication, and means at the dispatchers oiice controlled over said line circuits for indicating the movement of the vehicle along the trackway.

8. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections separated by stretches of single track, each siding section having a ramp rail adjacent each end thereof for controlling the entrance of a vehicle from the adjacent single track stretch into the siding section and each siding section having a ramp rail adjacent each end thereof for controlling the departure of the vehicle from the passing siding section, a dispatchers oiice, a line circuit extending from the dispatchers oice for each siding section and associated with said ramp rails of the siding section, means at the dispatchers oice for impressing tWo different kinds of currents upon the line circuits, a relay at each siding section associated with the line circuit and responsive to the polarity of one current in the line circuit for connecting to the line circuit the ramp rails for one or the other direction of train movement, means at the dispatchers office for changing the polarity of said one current in the line circuit, and a vehicle on the trackway having signal means responsive to the presence of a current in the ramp rails for displaying a proceed signal and responsive to the presence or absence of one kind of current in the ramp rail for displaying a main track and a side track indication.

9. In a railway dispatching system, a trackway having passing siding sections with main tracks and side tracks, said siding sections being separated by stretches of single track, each siding section having a signal station adjacent each end thereof for controlling the entrance of trains from the adjacent single track stretch into the siding section and each siding section having a signal station adjacent each end thereof for controlling the departure of trains from the passing siding section, each of the first mentioned signal stations including diiferentiated signals for indicating main track or side track operation and signal control means responsive to different kinds of currents supplied thereto for eiecting display of said differentiated signals, a dispatchers oice, a line circuit extending from said oiiice for each siding section and associated With the signal stations of the siding section, means at the dispatchers ofce for impressing different kinds of currents upon the line circuits, a relay at each siding section associated with the line circuit and responsive tothe polarity of a current in the line circuit for establishing the signal stations for one or the other direction of train movement, and means at the dispatchers ofce for changing the polarity of said current in the line circuit.

PAUL J. SIMMEN. 

